1. Field of the Invention
The present invention relates to an apparatus and method for determining a bit rate of audio content. More particularly, the present invention relates to an audio content bit rate determining apparatus and method capable of quickly and correctly identifying audio content compressed at a constant bit rate from among pieces of audio content compressed at a variable bit rate and the constant bit rate.
2. Description of the Related Art
The development and launching of portable audio devices have contributed to the quick spread in the use of MPEG Audio Layer-3 (MP3) files.
An MP3 compression scheme may adjust a bit rate in data transmission to obtain an excellent compression ratio while sound quality decreases. An MP3 format represents audio data as a sequence of frames, each frame having an independent bit rate. Each of the frames may have the same bit rate (Constant Bit Rate (CBR)) or a different bit rate (Variable Bit Rate (VBR)).
Since bit rates of audio frames of data compressed at a VBR are not constant, the bit rates of all of the audio frames should be identified to correctly obtain an average bit rate and a play time of the data. Because of this, the bit rate is important for acquiring audio information, such as a play time, or seeking for a song section to determine whether audio content, such as an MP3 file, has been compressed at a CBR or a VBR.
Accordingly, if the determination is not performed quickly, a method used for audio content compressed at a VBR should be used as well even for audio content compressed at a CBR that dominates most audio content, so an overhead is very large.
A very large overhead is consumed to distinguish a CBR from a VBR for play time information or seeking regardless of the fact that most pieces of audio content are compressed at a VBR. This causes a number of problems with popularization of smart phones having music playback functions, because a lot of resources and time are required for data scanning (e.g., an Android media scanning service, etc.) and management, as an amount of data to be managed increases in a geometric series. As a result, a song section seeking method is also based on a trial and error method for repeatedly seeking for a syncword at an incorrect position.